What Causes Severe Headaches And Lower Back Pain?

Hi I wonder if you can help. For the last three days I have been having severe headaches and lower back pain. Also pain in my upper body when walking quickly. I'm wondering if I have overdone things at the gym, I go four times a week and I found the last session quite tiring and wanted to stop but carried on till the end of my workout. I'm also having neck pain when I try to touch my chin on my chest. Im 49.